Heterojunction band offsets and dipole formation at BaTiO{sub 3}/SrTiO{sub 3} interfaces

Journal Article · Thu Nov 14 04:00:00 UTC 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4829695· OSTI ID:22217866

Balaz, Snjezana ^[1]; Zeng, Zhaoquan ^[2]; Brillson, Leonard J. ^[2]

---

1. Department of Physics and Astronomy, Youngstown State University, One University Plaza, Youngstown, Ohio 44555 (United States)
2. Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Lab, 2015 Neil Ave., Columbus, Ohio 43210 (United States)

We used a complement of photoemission and cathodoluminescence techniques to measure formation of the BaTiO{sub 3} (BTO) on SrTiO{sub 3} (STO) heterojunction band offset grown monolayer by monolayer by molecular beam epitaxy. X-ray photoemission spectroscopy (XPS) provided core level and valence band edge energies to monitor the valence band offset in-situ as the first few crystalline BTO monolayers formed on the STO substrate. Ultraviolet photoemission spectroscopy (UPS) measured Fermi level positions within the band gap, work functions, and ionization potentials of the growing BTO film. Depth-resolved cathodoluminescence spectroscopy measured energies and densities of interface states at the buried heterojunction. Kraut-based XPS heterojunction band offsets provided evidence for STO/BTO heterojunction linearity, i.e., commutativity and transitivity. In contrast, UPS and XPS revealed a large dipole associated either with local charge transfer or strain-induced polarization within the BTO epilayer.

• OSTI ID: 22217866
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 18 Vol. 114; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
CATHODOLUMINESCENCE
DEPTH
DIPOLES
FERMI LEVEL
FILMS
HETEROJUNCTIONS
INTERFACES
MOLECULAR BEAM EPITAXY
PHOTOEMISSION
STRAINS
STRONTIUM TITANATES
SUBSTRATES
ULTRAVIOLET RADIATION
WORK FUNCTIONS
X RADIATION
X-RAY PHOTOELECTRON SPECTROSCOPY